A popular type of mechanical bowstring release is the caliper-jaws type bowstring release. Caliper-jaws type bowstring releases are designed with caliper type jaws that are generally spring activated to move from a closed position to an open position when a trigger for the release is squeezed. An example of a caliper-jaws type bowstring is the Scott.TM. bowstring release. In use, the release usually is secured to the wrist by a strap with the working part of the release resting between the archer's thumb and index finger, being positioned so that the index finger can actuate the trigger. The jaws of the release are closed around the bowstring and the bowstring is withdrawn by pulling the release back. At the desired moment, the bowstring is released by actuating the trigger which opens the jaws. The advantage of such a release is that the bowstring is released smoothly without the "punching" which often accompanies manual release of the bowstring.
Purchasers of a caliper-jaws type bowstring release wish to have the jaws closely approximated, with little or no gap between them, when in a closed position. A release in which the jaws are not closely approximated when in the closed position will often be rejected by the scrutinizing consumer. Furthermore, a release in which the jaws are not closely approximated when in the closed position may not function properly and either fail to adequately close around the bowstring or permit premature release of the bowstring.
Manufacturing caliper-jaws type releases so that there is little or no gap between the jaws when in a closed position requires adherence to manufacturing tolerances which are expensive to maintain. Maintaining expensive manufacturing standards is not always practical when the product is a relatively inexpensive consumer item such as the caliper-jaws type bowstring release. The invention disclosed and claimed herein permits fine adjustment of the approximation of the jaws after manufacture and assembly of the release, thus relieving the manufacture of strict adherence to expensive manufacturing tolerances.